#3 It gives Bryan/Gulak something to do

The worst thing for a healthy Superstar is to not be used. It's frustrating because they know that they could be doing some great things in the ring if given the chance. While some stars get onto TV but don't do much, they at least get onto our screens. Waiting for Creative direction is also frustrating, but current angles need to play out and reset things sometimes.
Bryan has been a focal point of SmackDown ever since he returned from a brief retirement. He's proven that he's one of the best performers of the current generation so it makes sense that he's been featured in some type of program since his return. In my opinion, it would be an enormous waste of his immense talents if he wasn't used at all.
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In Gulak's case, he did have a run as Cruiserweight Champion. After dropping the title, he was drafted to SmackDown. But once he joined the Blue brand, he wasn't used that much. Working with Gulak is something that the former WWE Champion has gone on record of saying that he's always wanted to do. Now that the stars have aligned on SmackDown, the two performers can work with each other and decide who is the best with counters.